Abstract: An LED indicator system with at least one LED, and driving circuitry for driving the at least one LED. A power supply supplies a drive current to the at least one LED. A photodetector detects a luminous output of the at least one LED and correspondingly outputs a detection signal. A conditioning circuit removes signal components indicative of stray light from at least one source other than the at least one LED, for example from sunlight reflected off of an LED array including the at least one LED, from the detection signal. As a result, the conditioning circuit generates a synthesized intensity feedback signal to provide to the power supply. The LED indicator system and driving circuitry for the at least one LED may further include a controller which compares the current supplied by the power supply to the at least one LED with the synthesized intensity feedback signal. A transmitter may transmit a signal indicating a result of the comparison executed by the controller.

Abstract: Circuitry for driving an LED array and a lamp including such circuitry. A fixed current source outputs a fixed current to an LED array. A variable load is provided in parallel to the LED array to also receive an output from the fixed current power supply. The variable load senses a condition affecting a luminous output of the LED array and varies an impedance based on this sensed condition. This variable load may typically include a thermistor or a photodetector. As the impedance of the variable load changes, current diverted from the LED to the variable load changes. Thereby, current supplied to the LED array, and thereby the intensity LED, can be controlled based on the impedance changing element in the variable load.

Abstract: The present invention provides for a lamp assembly which can be utilized in overhead signaling or lighting applications such as in traffic signal lamps or illuminated overhead road signs. The assembly includes a lens that optimizes and redirects light in a desirable direction in order to meet certain regulations. The lens of the present invention is designed to power portions of light emitted from an LED while allowing other portions to pass through the lens unaided. The lens of the present invention works in combination with specific LEDs to efficiently redirect light emitted from the LEDs. The assembly includes a circuit board including a plurality of rows of LEDs and the lens, which has an exterior surface and an interior surface. The interior surface of the lens comprises a plurality of rows of horizontal bands with a single band being associated with a row of the LEDs.

Abstract: The present invention relates to an LED-illuminated lamp assembly which includes a lens that is capable of directing light from the LEDs both horizontally and vertically. The taillight mode is also directed slightly upward so as to comply with applicable lighting regulations. The lamp assembly also includes a current regulating assembly which is mounted within the housing and attached to a power source for providing current to LEDs positioned within the housing. The LEDs are mounted on an LED board assembly. The current regulating assembly is capable of maintaining steady current through the LEDs independent of the power source voltage so as to prevent an overheating of the LEDs at higher than normal voltages and to provide constant, non-flickering light output with varying input voltages.

Abstract: A method for determining the fibrinogen level of a patient blood plasma in an optical density based prothrombin time test. The method and apparatus utilize a novel parameter DELTA which factors out statistical inaccuracies associated with prior art test methods. The patient fibrinogen level is determined using DELTA points calculated from blood samples having known fibrinogen levels in the low, normal and high ranges. A piece wise function is then constructed around the DELTA points and the fibrinogen level of a patient blood sample is calculated using four equations pre-stored in a non-volatile memory.

Abstract: An improvement to an apparatus for receiving a sample of biological fluid containing non-fluid components. Prior art sample cell for use in conjunction with prior art analytical apparatus comprises two slidably engaged members, first member comprising a reservoir for holding fluid sample to be tested, second member adapted to receive fluid from an external filter in one section and adapted to receive reagent and exhibit reaction in another section. The improvement comprises means for preventing smearing of fluid when members are moved relative to each other. A channel collects overflow from reservoir in first member, conducting overflow to a barrier placed in gap between first and second member. A wiper shears excess fluid from behind barrier, generally out of gap between first and second member, when the first and second members are moved relative to each other.

Abstract: An apparatus for automatically performing analytical testing of individual distant samples of biological fluids wherein a test sample is reacted with test reagents and tested for a change in optical characteristics. A memory stores a plurality of different test protocols. An operator-actuated keyboard is used to select one of the test protocols from the memory. Individual distinct samples of biological fluid to be tested are received in a sample cell. The cell is heated to a preselected temperature. The apparatus transports an individual sample cell to a first location adapted to filter unwanted nonfluid material from the fluid to be tested and to remove excess fluid to be tested from the sample cell to cause a precise accurate volume of fluid to remain in the sample cell for testing.

Abstract: An apparatus for automatically performing analytical testing of individual distinct samples of biological fluids wherein a test sample is reacted with test reagents and tested for a change in optical characteristics. A memory stores a plurality of different test protocols. An operator-actuated keyboard is used to select one of the test protocols from the memory. Individual distinct samples of biological fluid to be tested are received in a sample cell. The cell is heated to a preselected temperature. The apparatus transports an individual sample cell to a first location adapted to filter unwanted nonfluid material from the fluid to be tested and to remove excess fluid to be tested from the sample cell to cause a precise accurate volume of fluid to remain in the sample cell for testing.

Abstract: An interference filter for the removal of power line interference from amplifying systems, such as electrocardiographs, which includes a band-rejection filter tuned to reject the power line frequency interference, a differential amplifier to which the signal being amplified and the output of the notch filter are applied to produce an output consisting of only the interference signal. The interference signal is fed to and stored in a memory which is constantly updated and the output of the memory is then summed with the original signal. Since the phase of the output of the memory is reversed from the interference in the original signal, only the original signal will result. An electronic switch is connected between the output of the differential amplifier and the memory and is operated by a velocity detector connected with the output of the band-rejection filter.

Abstract: Electrocardiographic apparatus including a novel and improved recording paper feed and lead switching arrangement which include a platen having a platen roller, both movable from an open position for installing a supply of recording paper to a position wherein the platen roller with recording paper fed about the surface thereof is moved to an operating position with the platen roller in recording engagement with a recording pen. A paper drive roller is positioned in adjoining relationship to the platen roller and engages the platen roller with the paper thereon when in the operating position. The recording paper is provided with spaced cue marks and transverse perforations between successive cue marks and the apparatus includes a cue detector and associated electric circuitry for detecting said cues so that heart muscle signals from successive groups of patient leads will be recorded on successive segments of the paper defined by the perforations.

Abstract: Filtering means for biophysical recording apparatus for removing interference from a signal source which includes a band rejection or notch filter and means for inserting the filter into the signal circuit when the signals have a certain characteristic and for removing the filter when the signals have another characteristic.